Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
High energy density metal air batteries, such as Zn-Air batteries, can be inexpensive to produce and are often viewed as environmentally friendly alternatives to other battery types. Metal air batteries are most commonly used as primary (non-rechargeable) batteries. As secondary (rechargeable) batteries, metal air battery cathodes may be prone to damage caused by oxygen gas generated within the cathode material during charging. Practical limits for recharging have been determined to be around 100 mA/cm2 in order to avoid cathode damage. Adopting a tubular cathode structure may allow for greater recharge potential by providing increased cathode surface area while remaining within the practical charge limit.